[COMMITTED] gccrs: Add testcase to show forward declared items work

[Arthur Cohen]

From: Philip Herron <philip.her...@embecosm.com>

Fixes #1006

gcc/testsuite/ChangeLog:

        * rust/compile/issue-1006.rs: New test.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/testsuite/rust/compile/issue-1006.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 gcc/testsuite/rust/compile/issue-1006.rs

diff --git a/gcc/testsuite/rust/compile/issue-1006.rs 
b/gcc/testsuite/rust/compile/issue-1006.rs
new file mode 100644
index 00000000000..7f565deaef3
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-1006.rs
@@ -0,0 +1,10 @@
+// { dg-options "-w" }
+union B {
+    a: A,
+    b: f32,
+}
+
+struct A {
+    data: i32,
+    len: usize,
+}
-- 
2.39.1